I have a Frigidaire freezer that is about 5 years old. I get ice build up inside the top of the door. The door appears to be closed.

The door gasket is leaking around the top of the door. Air getting in past the gasket condenses in the freezer causing the ice build-up.

This is just a general answer but it may mean that the door seal is leaking. Try running a dollar bill under the seal to see if that area is looser than the rest of the door seal.
Look inside the freezer for model number.
How to Check Freezer Door Seal DoItYourself com

Sounds like frost bulidup from door being left open warm air gets in making frost and ice. Need to turn off for 24hrs or so to let all the ice melt compleatey then turn back on keep door closed run for 24hrs check Temp. shoud be about 0 to -5 Deg. if good start using.

either you need to put spacers under the door on the door pin to raise it up.you may need to bend the doon. or replace the door gasket

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You have an air leak. Usually right where you frost build up is, however since hot air rises, sometimes this leak can be anywhere. Make sure your door closes tightly and your gaskets are clean and making good contact. You may have to adjust the gasket, adjust the door, or replace the door gasket. If there is ice on the floor of the freezer, you have a plugged drain line. In very rare instances we have found, where the freon lines enter the freezer, in the back or under the freezer, missing or fallen refrigeration putty that seals around the lines. Good Luck, Appliance Specialists

you probably have an air leak. if the gasket is bad it needs to be replaced. Air could also be coming in through the door flap if you have water and ice dispensor on door

This is the moisture coming out of the food. It is what causes freezer burn.

The problem is made worse in frost free models by the defrost cylce. Best way to slow it down is to use vacuum bags or freezer bags. Also above 0 F food deterioates faster and below it gets freezer burn and the moisture problem faster.

yea def , not normal, nor an acceptable amount of ice forming there( good pic). heres what i have been told to try and with good results
first make sure the door gasket is sealing all the way,(small gaps in ht emagnets at extreme corners) is common but with a little amount of "mortite"or "permagum can sometimes be insterted behind the corner of gasket to assist filling the void.
second a small amound of a white/clear silicone be applied to the outer perimtere of gasket, to minmize air movemnt from between gasket and door panel.
lastley in oyour second pic i see "frost free" written on a plastic air deflector. you can remove that with 3-4 screws on backside of it, and then reinstall with a small spacer so as the baffle now with sit with a 3/8in. gap between it and the top of the freezer liner.( a brass ferrel from the compression fitting of a plumbing fitting is just the right size)..... the theory behind this is to prevent the air from gatting "trapped" in the void created when the door closes-- air can now pass back and forth freely.
I hope this gives you some satisfaction if not I would advise another tech be sent who is willing to call for factore tech support( ths is where i got my info from)

Ice build-up in the area of the door could be causing the door gaskets to loose their seal. Shut the unit off and use a hair drier to melt the ice away from the door area. Return the control to run position and see if it makes a difference.

An upright freezer that is not frost free will have the coils in the shelves (shelves are non-removeable) and that is where the frost will buildup.  If your model is like this then it will have to be defrosted periodically.  If your not sure then give me the entire model # from the sticker inside the freezer and I will look it up for you.